A few members here have wanted to glass up a tire well enclosure. I did a "replace your back seat" enclosure a while back and today came the oportunity to do a well enclosure in a Swift. Here's how it works....
Wood to make a frame.
Fiberglass weave and/or chop mat.
Cheap paint brushes.
Acetone. (only if you plan on cleaning your brushes and re-using them) I buy a bunch of brushes and throw them away after each use.
Very well ventilated area.
1. First thing you want to do is completely cover the area your working on with foil and duct tape. This stops the resin from bonding to the car and rendering your enclosure impossible to remove once it's cured. You can't see it in the pic here because I've already covered it but I used a piece of cardboard to make a flat ledge on the bracket where the jack is supposed to be. I did this to stop the fiberglass from sinking into it and getting the enclosure stuck in the car once it wass cured. You want the layers of foil to overlap and make sure they are all sealed well with the tape.
this next pic just shows how far up I went in the back. You'd be suprised at how much resin can wick off of a brush and splatter onto things you don't want it on....
2. Once you have the foil all layed down nice you can start laying the glass. I prefer an extra measure of caution (you never know where there may be a small puncture in the foil that the resin will find) and I completely cover the foil with a layer of duct tape. This makes it a bit more time consuming but your guarantied that your box will pop out after it's cured. When the resin is curing it also melts the adhesive of the duct tape...makes it a little messier to pull of the enclosure...but also helps it pop out easier. Once your done covering the floor and everything is sealed your ready to go. I make a frame to attach the fiberglass to. This should actualy be step 1 which would bring the total steps up to 5 but I didn't take pics of it
. For this particular enclosure it measures 5" high but you can make it shallower. The sub going into this enclosure needs a lot of air so building up helped get the correct airspace. I used pine BTW because you can buy it in 10' lengths and it's way lighter than MDF. You can also see in this pic some clear plastic. I use this to seperate the front of the car from the back. This keeps all the smells from the resin to your work area and it doesn't stink up the rest of the car.
3. Everybody has their own way of laying glass. I prefer to cut my first and second layers to fit and then "tack" them down with a chunk of ducts tape. I also staple the edges to the frame. This ensures that when I start laying the resin it won't move as much. You will have to dab some resin on thise spots after you pop the enclosure out because the resin won't penetrate the tape. You'll see the dry spots when you flip the enclosure upside down. I use woven mat for my first layer because it holds together a bit better than chop but it really doesn't matter what you use. It's personal preference...and the weave costs a bit more. I use chop mat for the rest of the build.
4. Mix a batch of resin. I use 1L at a time on hot days because it cures faster. On "normal" days you can mix more once you get used to it and get a lot more layers done in once shot. Do read the mixing charts on your containers. Too cold a mix and it'll never cure...too hot and it'll start to smoke and crack. Cover every inch of the fiberglass and make sure that it soaks right through. Your first layer will look clear once it's saturated. Keep some torn chunks of chop matt in case you end up with pools of resin at the bottom of the enclosure. Soak these pools up by pressing in the chunks of mat. I use a 4" brush to paint the resin on. I keep a 2" brush with the bristles cut down to half their length to push air bubbles out of the resin as well as to push the resin into the mat. You usualy have about 10-12 minutes before the resin becomes to thick to use so work fast but don't go nuts. Once you get used to using fiberglass you can mix your batches hotter and save yourself a bit of time. My batched give me about 7 minutes. Doesn't sound like much but after 15-20 layers of mat those 3 minutes saved start to add up
. BTW...don't let the glass go over the edges of the frame. Your going to need it nice and flat for when you mount the baffle board to it. This pic shows a single layer on the sides and three for the base.
That's basically it in a nutshell. You'll want the thickness to be at least a 1/4" thick. It'll take a few layers to build it up that thick unless you have a heavier cloth. You can carefully pop the enclosure out after two layers of glass are in and finish the project out of the car though. After your layers are built up put a board (baffle) on top of the frame and mount your sub to it. The enclosure I'm working on will have a fiberglass top as well so I haven't got any pics of the board but you get the idea. All in all you should be able to complete a project like this in one day (using a baffle board) and it'll do wonders for the sound in your car. To do a fiberglass top will take a lot more time to properly build it and prep it for paint.
I'll keep this FAQ going once I get started on the top portion of the enclosure for those of you who wish to have something a little more shapely than a flat top.